One of the highest-profile trials to arise from the Toronto G20 summit began in earnest Monday, after defendant Byron Sonne lost a bid to have a host of evidence excluded from the process.

Despite the overwhelming publicity Mr. Sonne’s case has received, the first day of his trial proper was decidedly anti-climactic. Rather than delivering a sweeping opening statement, the Crown launched immediately into the minutiae of the case, spending hours cataloguing a series of photographs taken by police investigators in the accused’s basement laboratory.

Mr. Sonne, a Forest Hill computer expert, stands accused of plotting to attack the G20 summit in downtown Toronto in the summer of 2010. He stands charged with possessing explosive substances and counselling the commission of mischief not committed.

“We don’t know what he was planning to do with the explosives, but we do know that there was a fascination with the G20,” Crown attorney Elizabeth Nadeau said outside court.

Mr. Sonne, who has been highly critical of the merits of the prosecution, said the cache of chemicals found in his basement was simply the laboratory of a hobbyist; among other fascinations, the accused enjoyed amateur rocketry.

Supporters say Mr. Sonne’s flurry of social-media posts about the G20 in the days leading up to the 2010 world leaders’ conference – including derogatory comments about police and information about how to scale the security fence – was merely an attempt to explore the limits of summit security.

Those posts formed the backbone of an agreed statement of facts presented to Justice Nancy Spies Monday. The remainder of the day was consumed by the Crown painstakingly cataloguing dozens of photographs of the accused’s basement laboratory, complete with wires, plastic tubing, a black radio antenna and an enormous quantity of chemicals – jar after jar of everything from hydrogen peroxide to ammonium nitrate, each neatly labelled and stored on Mr. Sonne’s cluttered basement shelves.

“There were some materials of a concerning nature that were on scene,” said Detective Constable Irvin Albrecht, a forensic identification expert with the Toronto Police Service.

Asked about a photograph of two pieces of white plastic piping found in Mr. Sonne’s home, Det. Const. Albrecht remarked: “Items such as this have been used in the manufacture of explosive devices.”

Mr. Sonne, who sat behind his lawyers, shook his head vigorously in response.

A number of other items drew the attention of police photographers, including a book called the Encyclopedia of Serial Killers, a “suspected potato gun,” a listing of Toronto police radio codes and a map of the G20 security zone in the city’s downtown core.

Mr. Sonne had attempted to get a host of the Crown’s evidence excluded from trial, arguing police violated his Charter rights in obtaining it, but Judge Spies found the bulk of the contested evidence to be admissible.

During breaks Monday, Mr. Sonne’s family and supporters could be heard poking fun at the evidentiary photographs, questioning why the Crown highlighted an anti-static electronics bag and various other seemingly benign items.

Later in the week, the Crown was expected to call an explosives expert who could provide more insight into what the chemicals and electronic gadgets might have been used for.

Mr. Sonne’s wife, Kristen Peterson, was also arrested in the case but charges against her were later dropped. The couple’s marriage has since fallen apart.